Nickel-Cadmium Batteries

Nickel-Cadmium Batteries1. Rechargeable batteries are the main alternative to ordinary batteries. These are power sources where the chemical process is reversible: it goes in one direction when they are under load and in the other when they are under voltage. Thus, you do not have to throw away a rechargeable battery after use and buy a new one. You only need to recharge it to its full (or almost full) initial capacity. 2. We'll have a look at batteries used in light household electronic equipment. Nickel-cadmium batteries were created by the Swedish scientist Waldemar Junger in 1899. At that time, they were quite expensive. Moreover, they were not sealed: they released gas during the charging. It is only in the middle of the last century that a closed cycle nickel-cadmium battery was created. Gas released while charging was absorbed by the battery itself. 3. Batteries of this type have a nickel anode and a cadmium cathode. Nickel-cadmium batteries are popular with customers all over the world. Besides, they are relatively light and power-intensive. 4. Nickel-cadmium batteries are reliable and durable. They can be stored for up to 5 years and charged up to 1000 times if used correctly. They function well at low temperatures and sustain high charging currents. They can be charged by both low and high currents. Batteries feature a memory effect. The memory effect is a result of violation of the battery internal structure. Crystals grow in it, reducing the useful surface and, consequently, the capacity of the accumulator. It has been named so due to the fact that crystals grow especially quickly when the battery is not fully discharged, as if the battery "remembered" to what level the battery had been discharged last time. For example, if the battery is only discharged by 25%, the charging will restore its capacity not to 100% but less. To combat this memory effect, it is recommended to charge the battery only after complete discharge. Nickel-cadmium batteries are used even today due to low cost, durability and possibility of charging at low temperatures without negative consequences for the battery. 5. Nickel-cadmium batteries are used in various equipment as an alternative to the standard galvanic element, especially if the current consumption is high. In spite of development of other electrochemical systems and stricter ecological requirements, nickel-cadmium batteries are an unequalled and reliable solution with a big specific power, e.g. diving lamps. 6. Batteries are also used for powering portable equipment, tape recorders, household appliances and instruments, toys, etc.

Category:

Science & Technology

Tags:

• accumulator
• technology